Precipitation and snow cover variability in the french alps

2005 ◽  
pp. 81-92 ◽  
Author(s):  
Eric Martin ◽  
Yves Durand
Keyword(s):  
Snow Cover ◽  
French Alps

scholarly journals Past changes in natural and managed snow reliability of French Alps ski resorts from 1961 to 2018

2021 ◽  
Author(s):  
Lucas Berard-Chenu ◽  
Hugues François ◽  
Emmanuelle George ◽  
Samuel Morin
Keyword(s):  
Snow Cover ◽  
Positive Impact ◽  
Winter Season ◽  
Tourism Industry ◽  
Climatic Impact ◽  
Ski Resort ◽  
French Alps ◽  
Ski Resorts ◽  
Lower Elevation

Abstract. Snow reliability is a key climatic impact driver for the ski tourism industry, for which there is more literature regarding future projections than past observed impacts. This study provides an assessment of past changes in natural and managed snow cover reliability from 1961 to 2018 in the French Alps. In particular, we used snowmaking investment figures to infer the evolution of snowmaking coverage at the ski resort scale for 16 ski resorts in the French Alps. We find different benefits of snow management to reduce the variability and long term decrease in snow cover reliability because of the heterogeneity of the snowmaking deployment trajectories across ski resorts. The frequency of challenging conditions for ski resort operation over the 1991–2018 period increased in November and February to April compared to the reference period 1961–1990. In general, snowmaking had a positive impact on snow reliability, especially in December to January. While for the highest elevation ski resorts, snowmaking improved snow reliability for the core of the winter season, it did not counterbalance the decreasing trend in snow cover reliability for lower elevation ski resorts and in the spring.

scholarly journals Reanalysis of 47 Years of Climate in the French Alps (1958–2005): Climatology and Trends for Snow Cover

2009 ◽  
Vol 48 (12) ◽  
pp. 2487-2512 ◽  
Author(s):  
Yves Durand ◽  
Gérald Giraud ◽  
Martin Laternser ◽  
Pierre Etchevers ◽  
Laurent Mérindol ◽  
...  
Keyword(s):  
Snow Cover ◽  
Snow Depth ◽  
Numerical Models ◽  
High Elevation ◽  
Climatic Conditions ◽  
Spatial And Temporal Variability ◽  
The South ◽  
French Alps ◽  
Mountainous Regions ◽  
The North

Abstract Since the early 1990s, Météo-France has used an automatic system combining three numerical models to simulate meteorological parameters, snow cover stratigraphy, and avalanche risk at various altitudes, aspects, and slopes for a number of mountainous regions (massifs) in the French Alps and the Pyrenees. This Système d’Analyse Fournissant des Renseignements Atmosphériques à la Neige (SAFRAN)–Crocus–Modèle Expert de Prévision du Risque d’Avalanche (MEPRA) model chain (SCM), usually applied to operational daily avalanche forecasting, is here used for retrospective snow and climate analysis. For this study, the SCM chain used both meteorological observations and guess fields mainly issued from the newly reanalyzed atmospheric model 40-yr ECMWF Re-Analysis (ERA-40) data and ran on an hourly basis over a period starting in the winter of 1958/59 until recent past winters. Snow observations were finally used for validation, and the results presented here concern only the main climatic features of the alpine modeled snowfields at different spatial and temporal scales. The main results obtained confirm the very significant spatial and temporal variability of the modeled snowfields with regard to certain key parameters such as those describing ground coverage or snow depth. Snow patterns in the French Alps are characterized by a marked declining gradient from the northwestern foothills to the southeastern interior regions. This applies mainly to both depths and durations, which exhibit a maximal latitudinal variation at 1500 m of about 60 days, decreasing strongly with the altitude. Enhanced at low elevations, snow depth shows a mainly negative temporal variation over the study period, especially in the north and during late winters, while the south exhibits more smoothed features. The number of days with snow on the ground shows also a significant general signal of decrease at low and midelevation, but this signal is weaker in the south than in the north and less visible at high elevation. Even if a statistically significant test cannot be performed for all elevations and areas, the temporal decrease is present in all the studied quantities. Concerning snow duration, this general decrease can also be interpreted as a sharp variation of the mean values at the end of the 1980s, inducing a step effect in its time series rather than a constant negative temporal trend. The results have also been interpreted in terms of potential for a viable ski industry, especially in the southern areas, and for different changing climatic conditions. Presently, French downhill ski resorts are economically viable from a range of about 1200 m MSL in the northern foothills to 2000 m in the south, but future prospects are uncertain. In addition, no clear and direct relationship between the North Atlantic Oscillation (NAO) or the ENSO indexes and the studied snow parameters could be established in this study.

scholarly journals A meteorological estimation of relevant parameters for snow models

1993 ◽  
Vol 18 ◽  
pp. 65-71 ◽  
Author(s):  
Y. Durand ◽  
E. Brun ◽  
L. Merindol ◽  
G. Guyomarc'h ◽  
B. Lesaffre ◽  
...  
Keyword(s):  
Boundary Conditions ◽  
Snow Cover ◽  
Real Time ◽  
Meteorological Parameters ◽  
Meteorological Data ◽  
Observation Data ◽  
Meteorological Observation ◽  
French Alps ◽  
Snow Model

Relevant meteorological parameters have been analyzed to provide boundary conditions in real time for an energy, mass and stratigraphical model of snow cover at locations surrounded by meteorological observation points. From the available observation data, this analysis provides hourly meteorological information on every Alpine massif for six different aspects at 300 m elevation intervals. A numerical snow model has been run with these estimated meteorological data for numerous locations in the French Alps during the last ten years. Comparisons with observed snow characteristics (e.g., depth and stratigraphy) have proved the potential of the method.

scholarly journals Sensitivity of the French Alps snow cover to the variation of climatic variables

1994 ◽  
Vol 12 (5) ◽  
pp. 469-477 ◽  
Author(s):  
E. Martin ◽  
E. Brun ◽  
Y. Durand
Keyword(s):  
Snow Cover ◽  
Internal State ◽  
Regional Scale ◽  
Climatic Conditions ◽  
Meteorological Conditions ◽  
French Alps ◽  
Snow Model ◽  
Analysis System ◽  
The Impact ◽  
Data Period

Abstract. In order to study the sensitivity of snow cover to changes in meteorological variables at a regional scale, a numerical snow model and an analysis system of the meteorological conditions adapted to relief were used. This approach has been successfully tested by comparing simulated and measured snow depth at 37 sites in the French Alps during a ten year data period. Then, the sensitivity of the snow cover to a variation in climatic conditions was tested by two different methods, which led to very similar results. To assess the impact of a particular "doubled CO2" scenario, coherent perturbations were introduced in the input data of the snow model. It was found that although the impact would be very pronounced, it would also be extremely differentiated, dependent on the internal state of the snow cover. The most sensitive areas are the elevations below 2400 m, especially in the southern part of the French Alps.

Modulation of the snow cover changes in the French Alps and the Pyrenees by the deposition of light absorbing particles over the last 40 years 

2021 ◽  
Author(s):  
Marion Réveillet ◽  
Marie Dumont ◽  
Simon Gascoin ◽  
Matthieu Lafaysse ◽  
Pierre Nabat ◽  
...  
Keyword(s):  
Snow Cover ◽  
Regional Scale ◽  
Saharan Dust ◽  
Climate Projections ◽  
Dust Deposition ◽  
Economic Implications ◽  
French Alps ◽  
Dust Events ◽  
Long Term Impact ◽  
The Impact

<p>By darkening the snow surface, mineral dust and black carbon (BC) deposition accelerate snowmelt and triggers numerous feedbacks. Assessments of their long-term impact at the regional scale are still largely missing despite the environmental and socio-economic implications of snow cover changes. Using detailed snowpack simulations, we show that dust and BC deposition advance snowmelt by 17 days on average in the French Alps and the Pyrenees over the 1979-2018 period, with major implications for water availability and ground temperature. The effect of BC compared to dust is generally prevailing except in the Southern Pyrenees more exposed to Saharan dust events. We also quantify a contribution of BC and dust deposition up to 30% to the variance of the snow melt-out date. Lastly, we demonstrate that the decrease in BC deposition since the 80's alleviated the impact of current warming on snow cover decline. Therefore, this study highlights the importance of accounting for the inter-annual fluctuations in light absorbing particles deposition to improve the accuracy of snow cover reanalyses and climate projections.</p>

scholarly journals A meteorological estimation of relevant parameters for snow models

1993 ◽  
Vol 18 ◽  
pp. 65-71 ◽  
Author(s):  
Y. Durand ◽  
E. Brun ◽  
L. Merindol ◽  
G. Guyomarc'h ◽  
B. Lesaffre ◽  
...  
Keyword(s):  
Boundary Conditions ◽  
Snow Cover ◽  
Real Time ◽  
Meteorological Parameters ◽  
Meteorological Data ◽  
Observation Data ◽  
Meteorological Observation ◽  
French Alps ◽  
Snow Model

Relevant meteorological parameters have been analyzed to provide boundary conditions in real time for an energy, mass and stratigraphical model of snow cover at locations surrounded by meteorological observation points. From the available observation data, this analysis provides hourly meteorological information on every Alpine massif for six different aspects at 300 m elevation intervals. A numerical snow model has been run with these estimated meteorological data for numerous locations in the French Alps during the last ten years. Comparisons with observed snow characteristics (e.g., depth and stratigraphy) have proved the potential of the method.

scholarly journals Projected changes of snow conditions and avalanche activity in a warming climate: the French Alps over the 2020–2050 and 2070–2100 periods

2014 ◽  
Vol 8 (5) ◽  
pp. 1673-1697 ◽  
Author(s):  
H. Castebrunet ◽  
N. Eckert ◽  
G. Giraud ◽  
Y. Durand ◽  
S. Morin
Keyword(s):  
Climate Change ◽  
Snow Cover ◽  
21St Century ◽  
Mitigation Strategies ◽  
Climate Change Scenarios ◽  
Stability Estimates ◽  
Reference Period ◽  
French Alps ◽  
Wet Snow ◽  
Snow Conditions

Abstract. Projecting changes in snow cover due to climate warming is important for many societal issues, including the adaptation of avalanche risk mitigation strategies. Efficient modelling of future snow cover requires high resolution to properly resolve the topography. Here, we introduce results obtained through statistical downscaling techniques allowing simulations of future snowpack conditions including mechanical stability estimates for the mid and late 21st century in the French Alps under three climate change scenarios. Refined statistical descriptions of snowpack characteristics are provided in comparison to a 1960–1990 reference period, including latitudinal, altitudinal and seasonal gradients. These results are then used to feed a statistical model relating avalanche activity to snow and meteorological conditions, so as to produce the first projection on annual/seasonal timescales of future natural avalanche activity based on past observations. The resulting statistical indicators are fundamental for the mountain economy in terms of anticipation of changes. Whereas precipitation is expected to remain quite stationary, temperature increase interacting with topography will constrain the evolution of snow-related variables on all considered spatio-temporal scales and will, in particular, lead to a reduction of the dry snowpack and an increase of the wet snowpack. Overall, compared to the reference period, changes are strong for the end of the 21st century, but already significant for the mid century. Changes in winter are less important than in spring, but wet-snow conditions are projected to appear at high elevations earlier in the season. At the same altitude, the southern French Alps will not be significantly more affected than the northern French Alps, which means that the snowpack will be preserved for longer in the southern massifs which are higher on average. Regarding avalanche activity, a general decrease in mean (20–30%) and interannual variability is projected. These changes are relatively strong compared to changes in snow and meteorological variables. The decrease is amplified in spring and at low altitude. In contrast, an increase in avalanche activity is expected in winter at high altitude because of conditions favourable to wet-snow avalanches earlier in the season. Comparison with the outputs of the deterministic avalanche hazard model MEPRA (Modèle Expert d'aide à la Prévision du Risque d'Avalanche) shows generally consistent results but suggests that, even if the frequency of winters with high avalanche activity is clearly projected to decrease, the decreasing trend may be less strong and smooth than suggested by the statistical analysis based on changes in snowpack characteristics and their links to avalanches observations in the past. This important point for risk assessment pleads for further work focusing on shorter timescales. Finally, the small differences between different climate change scenarios show the robustness of the predicted avalanche activity changes.

scholarly journals Statistical adaptation of ALADIN RCM outputs over the French Alps – application to future climate and snow cover

2012 ◽  
Vol 6 (4) ◽  
pp. 785-805 ◽  
Author(s):  
M. Rousselot ◽  
Y. Durand ◽  
G. Giraud ◽  
L. Mérindol ◽  
I. Dombrowski-Etchevers ◽  
...  
Keyword(s):  
Snow Cover ◽  
Snow Water Equivalent ◽  
Climate Model ◽  
Regional Climate ◽  
Control Period ◽  
Shortwave Radiation ◽  
Change Scenario ◽  
Analysis Model ◽  
French Alps ◽  
Snow Model

Abstract. In this study, snowpack scenarios are modelled across the French Alps using dynamically downscaled variables from the ALADIN Regional Climate Model (RCM) for the control period (1961–1990) and three emission scenarios (SRES B1, A1B and A2) for the mid- and late 21st century (2021–2050 and 2071–2100). These variables are statistically adapted to the different elevations, aspects and slopes of the Alpine massifs. For this purpose, we use a simple analogue criterion with ERA40 series as well as an existing detailed climatology of the French Alps (Durand et al., 2009a) that provides complete meteorological fields from the SAFRAN analysis model. The resulting scenarios of precipitation, temperature, wind, cloudiness, longwave and shortwave radiation, and humidity are used to run the physical snow model CROCUS and simulate snowpack evolution over the massifs studied. The seasonal and regional characteristics of the simulated climate and snow cover changes are explored, as is the influence of the scenarios on these changes. Preliminary results suggest that the snow water equivalent (SWE) of the snowpack will decrease dramatically in the next century, especially in the Southern and Extreme Southern parts of the Alps. This decrease seems to result primarily from a general warming throughout the year, and possibly a deficit of precipitation in the autumn. The magnitude of the snow cover decline follows a marked altitudinal gradient, with the highest altitudes being less exposed to climate change. Scenario A2, with its high concentrations of greenhouse gases, results in a SWE reduction roughly twice as large as in the low-emission scenario B1 by the end of the century. This study needs to be completed using simulations from other RCMs, since a multi-model approach is essential for uncertainty analysis.

Sign in / Sign up

Export Citation Format

Share Document